It sounds slang to me, so I might be a bit wrong, but this is my take of it: I do not want/need to be associated with an idiot (like) you.

らんねえ = られない Liaison like "going to = Gonna" in English

Yes, it's very casual way of saying between close friends. I would translate it "I don't want to be involved with your idiot behavior..." Did you find this saying in Manga?